mirror of
https://github.com/sheumann/hush.git
synced 2024-08-16 09:29:16 +00:00
271 lines
5.9 KiB
C
271 lines
5.9 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
*
|
|
* mdev - Mini udev for busybox
|
|
*
|
|
* Copyright 2005 Rob Landley <rob@landley.net>
|
|
* Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
|
|
*
|
|
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#include "busybox.h"
|
|
#include "xregex.h"
|
|
|
|
#define DEV_PATH "/dev"
|
|
|
|
struct mdev_globals
|
|
{
|
|
int root_major, root_minor;
|
|
} mdev_globals;
|
|
|
|
#define bbg mdev_globals
|
|
|
|
/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
|
|
static void make_device(char *path, int delete)
|
|
{
|
|
char *device_name;
|
|
int major, minor, type, len;
|
|
int mode = 0660;
|
|
uid_t uid = 0;
|
|
gid_t gid = 0;
|
|
char *temp = path + strlen(path);
|
|
char *command = NULL;
|
|
|
|
/* Try to read major/minor string. Note that the kernel puts \n after
|
|
* the data, so we don't need to worry about null terminating the string
|
|
* because sscanf() will stop at the first nondigit, which \n is. We
|
|
* also depend on path having writeable space after it. */
|
|
|
|
if (!delete) {
|
|
strcat(path, "/dev");
|
|
len = open_read_close(path, temp + 1, 64);
|
|
*temp++ = 0;
|
|
if (len < 1) return;
|
|
}
|
|
|
|
/* Determine device name, type, major and minor */
|
|
|
|
device_name = strrchr(path, '/') + 1;
|
|
type = path[5]=='c' ? S_IFCHR : S_IFBLK;
|
|
|
|
/* If we have a config file, look up permissions for this device */
|
|
|
|
if (ENABLE_FEATURE_MDEV_CONF) {
|
|
char *conf, *pos, *end;
|
|
int line, fd;
|
|
|
|
/* mmap the config file */
|
|
fd = open("/etc/mdev.conf", O_RDONLY);
|
|
if (fd < 0)
|
|
goto end_parse;
|
|
len = xlseek(fd, 0, SEEK_END);
|
|
conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
|
|
close(fd);
|
|
if (!conf)
|
|
goto end_parse;
|
|
|
|
line = 0;
|
|
/* Loop through lines in mmaped file*/
|
|
for (pos=conf; pos-conf<len;) {
|
|
int field;
|
|
char *end2;
|
|
|
|
line++;
|
|
/* find end of this line */
|
|
for (end=pos; end-conf<len && *end!='\n'; end++)
|
|
;
|
|
|
|
/* Three fields: regex, uid:gid, mode */
|
|
for (field=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC);
|
|
field++)
|
|
{
|
|
/* Skip whitespace */
|
|
while (pos<end && isspace(*pos)) pos++;
|
|
if (pos==end || *pos=='#') break;
|
|
for (end2=pos;
|
|
end2<end && !isspace(*end2) && *end2!='#'; end2++)
|
|
;
|
|
|
|
if (field == 0) {
|
|
/* Regex to match this device */
|
|
|
|
char *regex = strndupa(pos, end2-pos);
|
|
regex_t match;
|
|
regmatch_t off;
|
|
int result;
|
|
|
|
/* Is this it? */
|
|
xregcomp(&match,regex, REG_EXTENDED);
|
|
result = regexec(&match, device_name, 1, &off, 0);
|
|
regfree(&match);
|
|
|
|
/* If not this device, skip rest of line */
|
|
if (result || off.rm_so
|
|
|| off.rm_eo != strlen(device_name))
|
|
break;
|
|
}
|
|
if (field == 1) {
|
|
/* uid:gid */
|
|
|
|
char *s, *s2;
|
|
|
|
/* Find : */
|
|
for (s=pos; s<end2 && *s!=':'; s++)
|
|
;
|
|
if (s == end2) break;
|
|
|
|
/* Parse UID */
|
|
uid = strtoul(pos, &s2, 10);
|
|
if (s != s2) {
|
|
struct passwd *pass;
|
|
pass = getpwnam(strndupa(pos, s-pos));
|
|
if (!pass) break;
|
|
uid = pass->pw_uid;
|
|
}
|
|
s++;
|
|
/* parse GID */
|
|
gid = strtoul(s, &s2, 10);
|
|
if (end2 != s2) {
|
|
struct group *grp;
|
|
grp = getgrnam(strndupa(s, end2-s));
|
|
if (!grp) break;
|
|
gid = grp->gr_gid;
|
|
}
|
|
}
|
|
if (field == 2) {
|
|
/* mode */
|
|
|
|
mode = strtoul(pos, &pos, 8);
|
|
if (pos != end2) break;
|
|
}
|
|
if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
|
|
// Command to run
|
|
const char *s = "@$*";
|
|
const char *s2;
|
|
s2 = strchr(s, *pos++);
|
|
if (!s2) {
|
|
// Force error
|
|
field = 1;
|
|
break;
|
|
}
|
|
if ((s2-s+1) & (1<<delete))
|
|
command = xstrndup(pos, end-pos);
|
|
}
|
|
|
|
pos = end2;
|
|
}
|
|
|
|
/* Did everything parse happily? */
|
|
|
|
if (field > 2) break;
|
|
if (field) bb_error_msg_and_die("bad line %d",line);
|
|
|
|
/* Next line */
|
|
pos = ++end;
|
|
}
|
|
munmap(conf, len);
|
|
end_parse: /* nothing */ ;
|
|
}
|
|
|
|
umask(0);
|
|
if (!delete) {
|
|
if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
|
|
if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
|
|
bb_perror_msg_and_die("mknod %s", device_name);
|
|
|
|
if (major == bbg.root_major && minor == bbg.root_minor)
|
|
symlink(device_name, "root");
|
|
|
|
if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
|
|
}
|
|
if (command) {
|
|
int rc;
|
|
char *s;
|
|
|
|
s = xasprintf("MDEV=%s", device_name);
|
|
putenv(s);
|
|
rc = system(command);
|
|
s[4] = 0;
|
|
putenv(s);
|
|
free(s);
|
|
free(command);
|
|
if (rc == -1) bb_perror_msg_and_die("cannot run %s", command);
|
|
}
|
|
if (delete) unlink(device_name);
|
|
}
|
|
|
|
/* Recursive search of /sys/block or /sys/class. path must be a writeable
|
|
* buffer of size PATH_MAX containing the directory string to start at. */
|
|
|
|
static void find_dev(char *path)
|
|
{
|
|
DIR *dir;
|
|
size_t len = strlen(path);
|
|
struct dirent *entry;
|
|
|
|
dir = opendir(path);
|
|
if (dir == NULL)
|
|
return;
|
|
|
|
while ((entry = readdir(dir)) != NULL) {
|
|
struct stat st;
|
|
|
|
/* Skip "." and ".." (also skips hidden files, which is ok) */
|
|
|
|
if (entry->d_name[0] == '.')
|
|
continue;
|
|
|
|
// uClibc doesn't fill out entry->d_type reliably. so we use lstat().
|
|
|
|
snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
|
|
if (!lstat(path, &st) && S_ISDIR(st.st_mode)) find_dev(path);
|
|
path[len] = 0;
|
|
|
|
/* If there's a dev entry, mknod it */
|
|
|
|
if (!strcmp(entry->d_name, "dev")) make_device(path, 0);
|
|
}
|
|
|
|
closedir(dir);
|
|
}
|
|
|
|
int mdev_main(int argc, char **argv);
|
|
int mdev_main(int argc, char **argv)
|
|
{
|
|
char *action;
|
|
char *env_path;
|
|
RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
|
|
|
|
xchdir(DEV_PATH);
|
|
|
|
/* Scan */
|
|
|
|
if (argc == 2 && !strcmp(argv[1],"-s")) {
|
|
struct stat st;
|
|
|
|
xstat("/", &st);
|
|
bbg.root_major = major(st.st_dev);
|
|
bbg.root_minor = minor(st.st_dev);
|
|
strcpy(temp,"/sys/block");
|
|
find_dev(temp);
|
|
strcpy(temp,"/sys/class");
|
|
find_dev(temp);
|
|
|
|
/* Hotplug */
|
|
|
|
} else {
|
|
action = getenv("ACTION");
|
|
env_path = getenv("DEVPATH");
|
|
if (!action || !env_path)
|
|
bb_show_usage();
|
|
|
|
sprintf(temp, "/sys%s", env_path);
|
|
if (!strcmp(action, "add")) make_device(temp,0);
|
|
else if (!strcmp(action, "remove")) make_device(temp,1);
|
|
}
|
|
|
|
if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
|
|
return 0;
|
|
}
|